I am still listening to Library: An Unquiet History by Matthew Battles. Here are two more interesting library innovations that Battles reports.
In the thirteenth century, librarians at the University of Sorbonne in Paris use the alphabet to organize the book collection. It seems to be the first instance of anyone using the alphabet to organize information.
Around the same time, librarians use Arabic numerals in the library catalog at Oxford University. What is cool about this is that the mathematicians of Europe are still resisting Arabic numerals, using Roman numerals for calculations. Librarians lead the way!
Battle also reports many terrible things librarian did through the centuries, especially resisting new scholarship because it was not classical. Some resisted the profusion of materials created after the invention of moveable type because there would be more books than any one man could ever read.
I'm still listening.